
Figure 1.
CBCT image analysis strategy.

Figure 2.
The frequency of the NPC type appearance.
Blue bars represents male subjects (n=63), pink bars represents female subjects (n=50).

Figure 3.
The dimensions at different sections of the nasopalatine canal and the horizontal diameter of the anterior maxilla (mm).A - different sections of NPC: A/1 - the mediolateral dimension of incisive foramen, A/2 - the anteroposterior dimension of the incisive foramen, A/3 - the anteroposterior dimension of the nasal foramen, A/4 - the nasopalatine canal length. B - horizontal diameter of anterior maxilla: B/1 - A level, B/2 - B level, B/3 - C level, B/4 - D level. Values are expressed as the mean ± SEM.
* Denotes a significant difference, p<0.05, ** denotes a significant difference, p<0.01.

Figure 4.
The dimensions of the NPC up to the NPC type in sagittal cross-section (in mm).
A - M-L dimension of the incisive foramen; B - A-P dimension of the incisive foramen; C - A-P dimension of the nasal foramen; D - NPC length. Values are expressed as the mean ± SEM.
Table 1.
The correlation between the dimension at different sections of the NPC and the anterior maxilla diameter at various levels (significant correlations are bolded, blue fields represent significant correlations only for male subjects, pink fields represent significant correlations only for female subjects, gray fields represent significant correlations for both gender).
| The sections of the NPC | Gender | The levels of anterior maxilla horizontal diameter | |||
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| A level | B level | C level | D level | ||
| The M-L dimension of incisive foramen | Male |
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| The A-P dimension of incisive foramen | Male |
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| The A-P dimension of nasal foramen | Male |
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| The NPC length | Male |
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Figure 5.
The horizontal diameter of the anterior maxilla at different levels according to the NPC type in sagittal cross-section (in mm). A - horizontal diameter of the anterior maxilla - A level; B - horizontal diameter of the anterior maxilla - B level; C - horizontal diameter of the anterior maxilla - C level; D - horizontal diameter of the anterior maxilla - D level. Values are expressed as the mean ± SEM.
Table 2.
The correlation between the M-L dimension of the incisive foramen and anterior maxilla diameter at various levels depending on the canal type at the sagittal cross-section (significant correlations are bolded, blue fields represent significant correlations only for male subjects, pink fields represent significant correlations only for female subjects, gray fields represent significant correlations for both gender).
| The correlation between the M-L dimension of incisive foramen and anterior maxilla diameter on different levels | Gender | The NPC type at the sagittal cross-section | |||
|---|---|---|---|---|---|
| Banana | Hourglass | Cylindrical | Funnel | ||
| The M-L dimension of incisive foramen vs. A level | Male |
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| The M-L dimension of incisive foramen vs. B level | Male |
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| The M-L dimension of incisive foramen vs. C level | Male |
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| The M-L dimension of incisive foramen vs. D level | Male |
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Table 3.
The correlation between the A-P dimension of the incisive foramen and the anterior maxilla diameter at various levels depending on the canal type at the sagittal cross-section (significant correlations are bolded, blue fields represent significant correlations only for male subjects, pink fields represent significant correlations only for female subjects, gray fields represent significant correlations for both gender).
| The correlation between the A-P dimension of nasal foramen and anterior maxilla diameter on different levels | Gender | The NPC type at the sagittal cross-section | |||
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| Banana | Hourglass | Cylindrical | Funnel | ||
| The A-P dimension of nasal foramen vs. A level | Male |
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| The A-P dimension of nasal foramen vs. B level | Male |
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| The A-P dimension of nasal foramen vs. C level | Male |
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| The A-P dimension of nasal foramen vs. D level | Male |
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Table 4.
The correlation between the A-P dimension of the nasal foramen and the anterior maxilla diameters at various levels depending on the canal type at the sagittal cross-section (significant correlations are bolded, blue fields represent significant correlations only for male subjects, pink fields represent significant correlations only for female subjects, gray fields represent significant correlations for both gender).
| The correlation between the A-P dimension of nasal foramen and anterior maxilla diameter on different levels | Gender | The NPC type at the sagittal cross-section | |||
|---|---|---|---|---|---|
| Banana | Hourglass | Cylindrical | Funnel | ||
| The A-P dimension of nasal foramen vs. A level | Male |
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| Female |
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| The A-P dimension of nasal foramen vs. B level | Male |
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| The A-P dimension of nasal foramen vs. C level | Male |
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| The A-P dimension of nasal foramen vs. D level | Male |
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Table 5.
The correlation between the nasopalatine canal length and anterior maxilla diameters at various levels depending on the canal type at the sagittal cross-section (significant correlations are bolded, blue fields represent significant correlations only for male subjects, pink fields represent significant correlations only for female subjects, gray fields represent significant correlations for both gender).
| The correlation between NPC length and anterior maxilla diameter on different levels | Gender | The NPC type at the sagittal cross-section | |||
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| Banana | Hourglass | Cylindrical | Funnel | ||
| NPC length vs. A level | Male |
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| NPC length vs. B level | Male |
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| NPC length vs. C level | Male |
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| NPC length vs. D level | Male |
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